SAN FRANCISCO — At 26 years old, Buster Posey already is a two-time World Series champion and the National League's Most Valuable Player. Now he could be a Giant for life. 

Posey and the Giants agreed to a nine-year contract on Friday, one that covers his three remaining arbitration years and buys out his first five years of free agency. The deal includes an option for 2022.

Posey had previously signed a one-year, $8 million deal to avoid arbitration and wasn't eligible to be a free agent until after the 2016 season. But the Giants have spent much of spring training quietly negotiating with Posey's agent, Jeff Berry, in an effort to lock the franchise catcher into a long-term deal.

Posey, a Georgia native, was the Giants' first-round pick in the 2008 draft and already has developed into the face of the franchise and one of the most recognizable and respected players in all of baseball. Both of his healthy seasons in the big leagues (2010, 2012) have ended with a ticker-tape parade down Market Street.

Posey is the reigning league MVP after a year in which he shook off months of ankle surgery rehab to hit a league-leading .336, with 24 homers and 103 RBIs. He is one of three catchers in history to win the Rookie of Year award, the MVP award and a World Series in his career.

This is the second consecutive year that the Giants have locked up a franchise cornerstone in the days before the season opener. Last April 2, the Giants announced a six-year, $127.5 million extension with ace Matt Cain. Two weeks later, Madison Bumgarner signed a five-year, $35 million extension.

Posey's deal has now blown both of those out of the water, along with every other contract the Giants have ever handed out.

Posey removes his cap during batting practice before an exhibition spring training baseball game against the Oakland Athletics, Thursday, March 28, 2013, in San Francisco. (AP Photo/Ben Margot)